食品科学

• 分析检测 • 上一篇    下一篇

光电型传感法快速检测食品中大肠杆菌

叶雨丹,柴春彦,刘国艳,王艺如   

  1. 上海交通大学农业与生物学院,上海 200240
  • 出版日期:2013-09-25 发布日期:2013-09-27

Development of Photoelectric Sensor for Detection of E. coli

YE Yu-dan,CHAI Chun-yan,LIU Guo-yan,WANG Yi-ru   

  1. School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
  • Online:2013-09-25 Published:2013-09-27

摘要:

大肠杆菌可在异丙基-β-D-硫代吡喃半乳糖苷(IPTG)的诱导下分泌β-半乳糖苷酶,β-半乳糖苷酶特异性的催化氯酚红-β-D-吡喃半乳糖苷(CPRG)生成氯酚红(CPR)发生显色反应,而反应颜色的深浅和大肠杆菌的浓度具有一定的对应关系,从而建立检测大肠杆菌的光电型传感方法。结果表明:用光电传感方法检测大肠杆菌,最适反应时间4h、最适反应pH7.5。样品中细菌浓度的对数与反射光信号值之间呈现良好的对应关系(R=-0.98944,P<0.01),线性方程为Y=1426.10485-97.23368X,检测限可达104CFU/mL。基于颜色反应的光电传感方法检测大肠杆菌具有快速、简便、成本低廉等优点,具有良好的研发和应用前景。

关键词: 大肠杆菌, 光电型传感器, &beta, -半乳糖苷酶, 光电型试纸条

Abstract:

E. coli secretes β-galactosidase under the induction of isopropyl-β-D-thiogalactopyranoside (IPTG). The
β-galacosidase catalyzes chlorophenol ReD-β-D-galactopyranoside (CPRG) to form chlorophenol red (CPR) along with
a color reaction. Based on the significant correlation between intensity of the color change from the reaction and the
concentration of E. coli, a photoelectric sensor for detecting E. coli was developed. The results showed that the optimal
pH for the reaction system was 7.5 and the optimal time for enzymatic reaction was 4 h. The logarithm value of bacterial
concentration in samples presented a significant correlation with the reflected light signal value (R = -0.98944, P < 0.01),
the linear equation was Y = 1426.10485 - 97.23368X. The detection limit was 104 CFU/mL. The photoelectric sensor based
on color reaction can provide a quick, simple and cheap way to detect E. coli in food samples and therefore deserves further
development and application.

Key words: E.coli;photoelectronic sensor;&beta, -galactosidase;photoelectric test strip